John A. Walker Jr., 77, the former U.S. Navy chief warrant officer who pleaded guilty to running one of the most damaging Soviet spy rings of the Cold War era, has died in a low-security federal prison in Butner, North Carolina, U.S. officials said Friday. No cause of death was given, but Walker was previously reported to have suffered from throat cancer.
Walker died Thursday, according to the prison. He was sentenced in 1986 to two life terms for supplying the then-Soviet Union with sensitive military data for almost two decades, in cahoots with his brother, Arthur, who died last month, and his son, among others. Walker was arrested after his ex-wife turned him in, saying he had tried to recruit their daughter.
In a 2010 retrospective on the case, the U.S. Naval Institute called the Walker spy operation "the biggest espionage leak in U.S. Navy history." Caspar Weinberger, President Ronald Reagan's defense secretary, said in 1987 that the information Walker passed along "enabled the KGB to decipher more than 1 million messages," which the Navy said allowed the Soviets to "restructure their own naval war plans."
— M. Alex Johnson